Un-break ecpg tests for Windows.

Un-break ecpg tests for Windows.

Declaring a function "inline" still doesn't work with Windows compilers
(C99? what's that?), unless the macro provided by pg_config.h is
in-scope, which it is not in our ECPG test programs.  So the workaround
I tried to use in commit 7640f9312 doesn't work for Windows.  Revert
the change in printf_hack.h, and instead just blacklist that file
in cpluspluscheck --- since it's a not-installed test file, we don't
really need to verify its C++ cleanliness anyway.